The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Moving Picture Experts Group (MPEG) and Video Coding Experts Group (VCEG) have developed an improved and excellent video compression technology over existing MPEG-4 Part 2 and H.263 standards. The new standard is named H.264/AVC (Advanced Video Coding) and was released simultaneously as MPEG-4 Part 10 AVC and ITU-T Recommendation H.264.
The video compression in such H.264/AVC (hereinafter referred to as ‘H.264’) involves various techniques of discrete cosine transform (DCT) of integer type, variable block size motion estimation and compensation, quantization, and entropy coding.
Video data encoding methods according to H.264 may be classified generally by prediction types into an intra prediction encoding and an inter-prediction encoding. Intra prediction predicts the current block to be encoded in a reference picture by using pixels of neighboring blocks with the current block. Inter-prediction uses the current block's closest block pixels in unidirectional or bidirectional reference pictures in predicting the current block.
Instead of encoding and compressing the entire image data, most video image compression techniques like the H.264 simply process the difference of the original pixels to the pixels predicted through the inter-prediction, intra prediction or the like in a way to remove the temporal and spatial redundancy. The smaller the difference of the predicted pixels from the original pixels, the smaller the image data becomes to be compressed which is translated into higher compression efficiency.
Therefore, in the video image compression space to improve the compression efficiency, there have been various prediction and encoding methods suggested to increase the prediction accuracy such as by determining either the inter-prediction or intra prediction depending on the image characteristics, prediction accuracy enhancement techniques, etc.
However, there are numerous reasons that the pixels cannot always be predicted accurately. In such a case, the deviations of the inaccurate pixels from the original pixels are excessive compared to other pixels. A residual signal of impulsive component refers to a larger one of the residual signals, which are the differences between the original pixels and predicted pixels, and the impulsive components have adverse effects on the video compression efficiency.